title: Wnt5a directs polarized calcium gradients by recruiting cortical endoplasmic reticulum to the cell trailing edge.
abstract: Wnt5a directs the assembly of the Wnt-receptor-actin-myosin-polarity (WRAMP) structure, which integrates cell-adhesion receptors with F-actin and myosin to form a microfilament array associated with multivesicular bodies (MVBs). The WRAMP structure is polarized to the cell posterior, where it directs tail-end membrane retraction, driving forward translocation of the cell body. Here we define constituents of the WRAMP proteome, including regulators of microfilament and microtubule dynamics, protein interactions, and enzymatic activity. IQGAP1, a scaffold for F-actin nucleation and crosslinking, is necessary for WRAMP structure formation, potentially bridging microfilaments and MVBs. Vesicle coat proteins, including coatomer-I subunits, localize to and are required for the WRAMP structure. Electron microscopy and live imaging demonstrate movement of the ER to the WRAMP structure and plasma membrane, followed by elevation of intracellular Ca2+. Thus, Wnt5a controls directional movement by recruiting cortical ER to mobilize a rear-directed, localized Ca2+ signal, activating actomyosin contraction and adhesion disassembly for membrane retraction.
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309, USA.
authors.forename: Eric S
authors.initials: ES
authors.lastname: Witze
authors.forename: Mary Katherine
authors.initials: MK
authors.lastname: Connacher
authors.forename: Stephane
authors.initials: S
authors.lastname: Houel
authors.forename: Michael P
authors.initials: MP
authors.lastname: Schwartz
authors.forename: Mary K
authors.initials: MK
authors.lastname: Morphew
authors.forename: Leah
authors.initials: L
authors.lastname: Reid
authors.forename: David B
authors.initials: DB
authors.lastname: Sacks
authors.forename: Kristi S
authors.initials: KS
authors.lastname: Anseth
authors.forename: Natalie G
authors.initials: NG
authors.lastname: Ahn
mesh_terms: D000199:Actins / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D016764:Cell Polarity; D020756:Coatomer Protein / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D008870:Microtubules / Q000378:metabolism; D046912:Multiprotein Complexes / Q000378:metabolism / Q000648:ultrastructure; D009218:Myosins / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D060490:Receptors, Wnt / Q000378:metabolism; D051153:Wnt Proteins / Q000378:metabolism*; D000071818:Wnt-5a Protein; D020703:ras GTPase-Activating Proteins / Q000378:metabolism
chemical_list: D000199:Actins; D020756:Coatomer Protein; C101203:IQ motif containing GTPase activating protein 1; D046912:Multiprotein Complexes; D011518:Proto-Oncogene Proteins; D060490:Receptors, Wnt; C085389:WNT5A protein, human; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; D020703:ras GTPase-Activating Proteins; D009218:Myosins; D002118:Calcium